Chromosome numbers and karyotype evolution in holoparasitic Orobanche (Orobanchaceae) and related genera

American Journal of Botany
By: , and 

Links

Abstract

Chromosome numbers and karyotypes of species of OrobancheCistanche, and Diphelypaea (Orobanchaceae) were investigated, and 108 chromosome counts of 53 taxa, 19 counted for the first time, are presented with a thorough compilation of previously published data. Additionally, karyotypes of representatives of these genera, including Orobanche sects. Orobanche and Trionychon, are reported. Cistanche (x = 20) has large meta- to submetacentric chromosomes, while those of Diphelypaea (x = 19) are medium-sized submeta- to acrocentrics. Within three analyzed sections of Orobanche, sects. Myzorrhiza (x = 24) and Trionychon (x = 12) possess medium-sized submeta- to acrocentrics, while sect. Orobanche (x = 19) has small, mostly meta- to submetacentric, chromosomes. Polyploidy is unevenly distributed in Orobanche and restricted to a few lineages, e.g., O. sect. Myzorrhiza or Orobanche gracilis and its relatives (sect. Orobanche). The distribution of basic chromosome numbers supports the groups found by molecular phylogenetic analyses: Cistanche has x = 20, the Orobanche-group (Orobanche sect. OrobancheDiphelypaea) has x = 19, and the Phelipanche-group (Orobanche sects. GymnocaulisMyzorrhizaTrionychon) has x = 12, 24. A model of chromosome number evolution in Orobanche and related genera is presented: from two ancestral base numbers, xh = 5 and xh = 6, independent polyploidizations led to x = 20 (Cistanche) and (after dysploidization) x = 19 (Orobanche-group) and to x = 12 and x = 24 (Phelipanche-group), respectively.

Publication type Article
Publication Subtype Journal Article
Title Chromosome numbers and karyotype evolution in holoparasitic Orobanche (Orobanchaceae) and related genera
Series title American Journal of Botany
DOI 10.3732/ajb.91.3.439
Volume 91
Issue 3
Year Published 2004
Language English
Publisher Wiley
Contributing office(s) Western Fisheries Research Center
Description 10 p.
First page 439
Last page 448
Google Analytic Metrics Metrics page
Additional publication details